Feedback: "moz-win-glass" Removed (109.0?)

[DBN]

I started up Firefox last night and found that every window (except #1, see bottom) was 100% invisible. After some investigations today, I found that removing this entry from userChrome.css fixes the invisibility problem:

#main-window {
  background-color: transparent !important;
  -moz-appearance: -moz-win-glass !important;
}

So I guess this means moz-win-glass was secretly removed. Possibly it was removed in 109.0 and I didn't approve the update until the computer crashed. I have confirmed the issue by installing the same userChrome on another profile. (On that profile, which I accessed via RDP, the windows are visible and the glass regions are completely transparent, further indicating the removal of moz-win-glass. Not sure why there is a difference, unless it's due to how Windows RDP rendering works.)

moz-win-glass was a small feature that sent a request to the OS to extend the title bar "transparent glass" region through the whole window. The glass feature was officially only available in Windows Vista and Windows 7 (and maybe Windows 11?), but tools like Glass8 have been available to patch the feature back into the OS. (Glass8 has a reputation of being hard to use due to breaking on new OS versions but is actually easy to use on LTS versions of Windows and Windows Server.)

I don't know how many people still use Glass8 etc but it's disappointing to see this feature removed. I hope it was at least removed for a good reason rather than on impulse. Thanks for leaving it in as long as you did.

Here was my full userChrome.css for the record:

/* open the debugger with ctrl+alt+shift+i on the browser window you want to debug */

/***** glass *****/

#main-window {
  background-color: transparent !important;
  -moz-appearance: -moz-win-glass !important;
  --userscript-content-border: 1px solid rgba(0,0,0,0.6);
}
#navigator-toolbox {
  background-color: transparent !important;
}
tab .tab-background {
  /* pull the tabs down flush with the toolbar */
  margin-bottom: 0 !important;
  border-bottom-left-radius: 0 !important;
  border-bottom-right-radius: 0 !important;
}
tab[visuallyselected="true"] .tab-background,
tab[multiselected] .tab-background {
  border: var(--userscript-content-border) !important;
  border-bottom: none !important;
}

toolbox > toolbar:first-of-type {
  border-top: var(--userscript-content-border) !important;
}
#main-window:not([sizemode="maximized"]) toolbox > toolbar {
  border-left: var(--userscript-content-border) !important;
  border-right: var(--userscript-content-border) !important;
}
#main-window:not([sizemode="maximized"]) #browser {
  border-left: var(--userscript-content-border) !important;
  border-right: var(--userscript-content-border) !important;
  border-bottom: var(--userscript-content-border) !important;
}

#titlebar-buttonbox-container .toolbarbutton-icon {
  /*
  hide the icons on the top right window buttons, which makes them completely transparent when not hovering over them.
  the system buttons are then completely visible even though they aren't what the user will actually be clicking on
  */
  visibility: hidden;
}
#TabsToolbar .tab-text:not([selected]),
#toolbar-menubar {
  text-shadow: 0px 0px 4px #FFF, 0px 0px 6px #FFF;
  color: #000;
}
#TabsToolbar .tab-label-container {
  /* keep the shadow from getting cut off on the left side */
  margin-left: -6px;
  padding-left: 6px;
}

/***** tab readability *****/

#TabsToolbar tab:not([pinned]) .tab-content {
  padding-right: 0px !important; /* no spacing between the faded end of the text and the tab edge */
}

@media (orientation: portrait) {
  #TabsToolbar tab:not([pinned]) .tab-icon-image {
    margin-inline-end: 1px !important; /* pull the tab title closer to the favicon */
  }
  #TabsToolbar tab:not([pinned]) .tab-content {
    padding-left: 1px !important; /* minimal spacing between the icon and the tab edge */
    padding-right: 0px !important; /* no spacing between the faded end of the text and the tab edge */
  }
  #TabsToolbar #tabbrowser-tabs {
    --tab-min-width: 16px !important;
  }
}

An old screenshot of how this looked is attached.

(This theme never properly worked on window #1, I never bothered to figure out why but that was also the only window that still worked after the error.)

[FirefoxEnjoyer]

Should Moizzla fix it or the dev that made Glass8 or both?